From U2.com: 

U2 have recorded John Lennon’s ‘Instant Karma’ for an Amnesty album drawing attention to the crisis in Darfur. It’s out next week.

More than 50 artists are taking part in the Amnesty International campaign which combines the music of John Lennon with new technology and human rights activism.

Highlights include: U2 (“Instant Karma”), Green Day (“Working Class Hero”), R.E.M. (“#9 Dream”); Jackson Browne (“Oh My Love”); Christina Aguilera (“Mother”), Avril Lavigne (“Imagine”), Corinne Bailey Rae (“I’m Losing You”); Snow Patrol (“Isolation”), The Flaming Lips (“(Just Like) Starting Over”) Regina Spektor (“Real Love”); Lenny Kravitz (“Cold Turkey”); Los Lonely Boys (“Whatever Gets You Thru the Night”); Jakob Dylan with Dhani Harrison (“Gimme Some Truth”) and Ben Harper (“Beautiful Boy”).

It also appears the new album is coming along:

U2 are in Africa, writing songs with Daniel Lanois and Brian Eno.

The band have set up a studio in Morocco’s medieval city of Fez where they have been writing and recording from morning till night for the past couple of weeks.

‘There’s no word on what the new material is for,’ according to one of the team in Fez. ‘But they’re on a roll and the ideas are coming thick and fast.’